1. Field of the Invention
The present invention relates to a tool for a soil cultivating machine, of the type having a rotor rotatable about a vertical or substantially vertical axis, and provided, at its periphery, with soil cultivating interchangeable tools. It also relates to soil cultivating machines using these tools, such as weeding machines, hoeing machines, vineyard plows, etc., all of which are adapted to root out and/or to shred weeds and noxious plants and/or to loosen the ground surface.
2. Background and Material Information
The current configuration of tools for hoeing or similar ground-working operation, used in machines of the aforementioned type, does not take into account all of the problems due to the rotation of these tools in the ground, such as resistance to penetration, rapid wear, resistance of the lumps to break up, violence of impacts upon striking stones, etc., such that their efficiency as well as their possible period of service are affected.
For example, the document DE-3.341.040 A shows, in FIGS. 4 and 4a, an agricultural soil cultivating machine having a fixing end located in an upper spatial zone, a connecting, portion located in an intermediate spatial zone, and an active portion located in a lower spatial zone. The fixing end of this tool is provided with two holes enabling the tool to be positioned fixedly, by means of bolts, on a rubber rotatable plate. This mounting of the tools on a relatively flexible support is inadequate in efficiently protecting the sharp edges of the tools when they strike stones or other hard bodies during operation. One can imagine that the tools are quickly put out of service.
The document U.S. Pat. No. 9,915,364 shows a rotary cultivator also having a fixing end located in an upper spatial zone, a connecting portion located in an intermediate spatial zone, and an active portion located in a lower spatial zone. The fixing end of this tool is housed in a hole of the rotatable hub, and it is fixed by means of a pin, whereas its intermediate portion extends through a slot provided in the cylindrical side wall of the hub.
One of the objects of the invention described in this document is to make it possible to attach the tools in either one of two possible positions corresponding to two diameters of the hoeing heads. In this case also, the tools are fixedly positioned on the rotatable hub, such that they are very exposed to impacts that shorten their period of service.
An object of the invention is to propose a tool and a machine providing a better solution to the aforementioned problems.
According to the invention, there is provided an interchangeable tool including, in view of its normal operative position: a fixing end located in an upper space zone, this end being arranged or configured so as to enable it to be mounted, with freedom of pivoting, on the rotor of a soil cultivating machine, such as a weeding machine or a similar machine; a connecting portion located in an intermediate spatial zone and extending downwardly from the fixing end; and an active portion located in a lower space zone. The connecting portion can advantageously have an inclined position with respect to the fixing end and the active portion, such that the latter are distant from one another, both in the vertical direction and in the horizontal direction.
Due to these arrangements, the tools penetrate more easily into the ground; they are subject to less substantial frictions, such that they wear out less quickly; and these advantages yield another advantage constituted by a lower energy consumption.
Furthermore, the tools are tensioned by the centrifugal force when the rotor rotates, and they retract by pivoting on their fixing axis, when they encounter a rock or other hard obstacle.
According to another characteristic arrangement, the active portion of the tool extends forwardly, considering the direction of rotation of me tool during operation, from the distal end of the connecting portion.
Due to this arrangement, the lower active portion of the tool has a substantial reserve of material, and can durably and efficiently fulfil its function, despite a substantial wear.
According to an alternative embodiment, the sharp leading edge of the lower active portion of the tools is curved, and the active portion extends rearwardly, considering the direction of rotation of the tool during operation, from the distal end of the connecting portion.
This tool is better suited to soils covered with thick grass due to its self-unclogging effect that prevents clogging.
Furthermore, although it is provided to obtain the tool in a single piece, the active portion or at least the front portion of the active portion of the tool could be interchangeable or attached, by screwing, welding or otherwise, this front portion then being made out of a very hard material such as tungsten carbide, stellite, etc., or having been previously subject to hard coatings by pelletizing, powdering, projection, etc., whereas the remaining portion the tool is made of a softer and less expensive material (such as steel, for example).
According to another characteristic arrangement, the front portion of the active portion of the tool is inclined forwardly, the lower surface of the front portion advantageously forming a small rake angle, with a plane perpendicular to the pivoting axis of the tool.
This arrangement makes it possible to avoid the xe2x80x9cslip heel soil pressurexe2x80x9d and to preserve the operating depth, despite the wear.
According to another characteristic arrangement, the upper surface of the active portion of the tool includes a boss located after its front portion, considering its direction of rotation, this boss making it possible to pulverize the ground.
The weeding machine according to the invention is characterized in that its rotor is arranged so as to enable the mounting, with freedom of pivoting, of at least two previously described tools, preferably under conditions such that when they are installed on the rotor, their pivoting axes converge downwardly toward the axis of rotation of the latter, by forming an angle with the axis of rotation.
As indicated previously, when the tools encounter an obstacle, they retract by pivoting rearwardly about their pivoting axis, thus absorbing the impacts and preventing the weeding machine head assembly from becoming unstable. During such a retracting phase (which can result either from striking a hard obstacle such as a stone or the like, or from an excessive compactness of the ground), the operating depth is reduced due to the aforementioned angle, which makes it possible to avoid the obstacle and to limit the torque and, therefore, the power to be transmitted to maintain the rotating speed of the rotor.
The invention also provides for a device for a soil cultivating machine, comprising a rotor. A plurality of tools are mounted to the rotor. At least one tool of the plurality comprises a fixing end, a soil engaging portion, and a connecting portion which connects the fixing end to the soil engaging portion. The at least one tool is movably mounted to the rotor.
The fixing end of the at least one tool may be pivotally mounted to the rotor. The soil cultivating machine may comprise one of a weeding machine, a hoeing machine, and a vineyard plow. The at least one tool may be interchangeably mounted to the rotor. The connecting portion may be arranged to be inclined relative to a center axis running through the rotor. The soil engaging portion may extend radially outwards from the fixing end. The fixing end may comprise a ring adapted to receive a journal axle, the journal axle movably mounting the fixing end to the rotor. The at least one tool comprises a shape which resembles a hook or an xe2x80x9cLxe2x80x9d. The soil engaging end may comprise a leading edge and at least one curved portion.
The soil engaging portion may comprise a sharp leading edge and at least one curved surface. The soil engaging portion may have an inclined portion and includes a first lower surface and a second lower surface, the first lower surface being arranged above the second lower surface when the at least one tool is mounted to the rotor. The soil engaging portion may comprise a boss portion.
The rotor may be rotatably mounted to the soil cultivating machine. Each of the plurality of tools may be pivotally mounted to the rotor. Each of the tools may be adapted to pivot freely between an angle of 0xc2x0 to 180xc2x0 or more. Alternatively, each of the tools may be adapted to pivot freely between an angle of 45xc2x0 to 65xc2x0. Each of the tools may be mounted about an axis which is not parallel to a center axis of the rotor. The at least one tool may be mounted about an axis which is not parallel to a center axis of the rotor.
The device may further comprise a guide arranged adjacent the rotor. The device may further comprise a fixing flange arranged to help retain the at least one tool on the rotor.
The invention also provides for a device for a soil cultivating machine, comprising a rotor adapted to be rotatably mounted to the soil cultivating device. A plurality of tools are interchangeably mounted to the rotor. Each of the plurality of tools comprises a fixing end, a soil engaging portion, and a connecting portion which connects the fixing end to the soil engaging portion. Each fixing end is movably fixed to the rotor via an axle. Each soil engaging portion comprises a curved member having a leading edge. A mechanism biases the tools against the rotor.
The invention further provides for a device for a soil cultivating machine, comprising a rotor adapted to be rotatably mounted to the soil cultivating device. A plurality of tools are interchangeably mounted to the rotor. Each of the plurality of tools comprises a fixing end, a soil engaging portion, and a connecting portion which connects the fixing end to the soil engaging portion. Each fixing end comprises a ring portion which is movably fixed to the rotor via an axle. Each soil engaging portion is arranged below the ring portion and comprises a plate like member having a leading edge. A mechanism biases the tools against the rotor. Each of the axles is oriented at an angle relative of a center axis of the rotor.